[Sur la nature particulière de la turbulence dans les noyaux planétaires]
Sous les contraintes combinées de la rotation rapide, de la sphéricité et du champ magnétique, les écoulements dans les noyaux planétaires s'organisent d'une manière particulière. La turbulence hydrodynamique classique n'est pas présente mais des mouvements turbulents peuvent se mettre en place sous l'action des forces d'Archimède et de Lorentz. Des expériences de laboratoire comme l'expérience DTS de Couette sphérique sous champ magnétique à Grenoble, nous aident à comprendre les écoulements qui peuvent exister dans les conditions des noyaux planétaires.
Under the combined constraints of rapid rotation, sphericity, and magnetic field, motions in planetary cores get organized in a peculiar way. Classical hydrodynamic turbulence is not present, but turbulent motions can take place under the action of the buoyancy and Lorentz forces. Laboratory experiments, such as the rotating spherical magnetic Couette DTS experiment in Grenoble, help us understand what motions take place in planetary core conditions.
Mots-clés : Dynamo, Noyau planétaire, DTS, Couette sphérique
Henri-Claude Nataf 1 ; Nadège Gagnière 1
@article{CRPHYS_2008__9_7_702_0, author = {Henri-Claude Nataf and Nad\`ege Gagni\`ere}, title = {On the peculiar nature of turbulence in planetary dynamos}, journal = {Comptes Rendus. Physique}, pages = {702--710}, publisher = {Elsevier}, volume = {9}, number = {7}, year = {2008}, doi = {10.1016/j.crhy.2008.07.009}, language = {en}, }
Henri-Claude Nataf; Nadège Gagnière. On the peculiar nature of turbulence in planetary dynamos. Comptes Rendus. Physique, Dynamo effect: experimental progress and geo- and astro-physical challenges / Effet dynamo : avancées expérimentales et défis géo- et astrophysiques, Volume 9 (2008) no. 7, pp. 702-710. doi : 10.1016/j.crhy.2008.07.009. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2008.07.009/
[1] Generation of magnetic field by a turbulent flow of liquid sodium, Phys. Rev. Lett., Volume 98 (2006), p. 044502
[2] Magnetic field reversals in an experimental turbulent dynamo, Eur. Phys. Lett., Volume 77 (2007), p. 59001
[3] Magnetic Field Saturation in the Riga dynamo experiment, Phys. Rev. Lett., Volume 86 (2001), pp. 3024-3027
[4] Experimental demonstration of a homogeneous two-scale dynamo, Phys. Fluids, Volume 13 (2001), pp. 561-564
[5] The magneto-hydrodynamics of a rotating fluid and the Earth's dynamo problem, Proc. R. Soc. Lond. A, Volume 274 (1963), pp. 274-283
[6] Experimental study of super-rotation in a magnetostrophic spherical Couette, Geophys. Astrophys. Fluid Dyn., Volume 100 (2006), pp. 281-298
[7] Rotating spherical Couette flow in a dipolar magnetic field: Experimental study of magneto-inertial waves, J. Fluid Mech., Volume 604 (2008), pp. 175-197
[8] H.-C. Nataf, T. Alboussière, D. Brito, P. Cardin, N. Gagnière, D. Jault, D. Schmitt, Rapidly rotating spherical Couette flow in a dipolar magnetic field: An experimental study of the mean axisymmetric flow, Phys. Earth Planet. Inter. (2008), doi: | DOI
[9] Towards a rapidly rotating liquid sodium dynamo experiment, Magnetohydrodynamics, Volume 38 (2002), pp. 177-189
[10] Axial invariance of rapidly varying diffusionless motions in the Earth's core interior, Phys. Earth Planet. Inter., Volume 166 (2008), pp. 67-76
[11] Axisymmetric flow between differentially rotating spheres in a dipolemagnetic field, J. Fluid Mech., Volume 344 (1997), pp. 213-244
[12] Inertial waves driven by differential rotation in a planetary geometry, Geophys. Astrophys. Fluid Dyn., Volume 101 (2007), pp. 469-487
[13] Quasi-geostrophic flows responsible for the secular variation of the Earth's magnetic field, Geophys. J. Int., Volume 173 (2008), pp. 421-443
[14] Boundary layer instability at the top of the Earth's outer core, J. Comput. Appl. Math., Volume 166 (2004), pp. 123-131
[15] Dissipation at the core-mantle boundary on a small-scale topography, J. Geophys. Res., Volume 111 (2006), p. B04413
[16] Magnetic and viscous coupling at the core-mantle boundary: inferences from observations of the Earth's nutations, Geophys. J. Int., Volume 171 (2007), pp. 145-152
[17] Modeling nutation and precession: very long baseline interferometry results, J. Geophys. Res. 107 (2002) (B4, 2069)
[18] Quasi-geostrophic kinematic dynamos at low magnetic Prandtl numbers, Earth Planet. Sci. Lett., Volume 245 (2006), pp. 595-604
[19] Commutation error correction for large eddy simulations of convection driven dynamos, Geophys. Astrophys. Fluid Dyn., Volume 101 (2007), pp. 429-449
[20] Torsional magnetohydrodynamic vibrations in the Earth's core and variations in day length, Geomag. Aeron., Volume 10 (1970), pp. 1-8
[21] Torsional oscillations and the magnetic field within the Earth's core, Nature, Volume 388 (1997), pp. 760-763
[22] Torque balance, Taylor's constraint and torsional oscillations in a numerical model of the geodynamo, Phys. Earth Planet. Int., Volume 140 (2003), pp. 29-51
[23] Westward drift, core motions and exchanges of angular momentum between core and mantle, Nature, Volume 333 (1988), pp. 353-356
[24] Investigation of a secular variation impulse using satellite data: the 2003 geomagnetic jerk, Earth Planet. Sci. Lett., Volume 255 (2007), pp. 94-105
[25] Geomagnetic dynamo: an improved laboratory model, Nature, Volume 219 (1968), pp. 717-718
- Dynamic regimes in planetary cores: τ–ℓ diagrams, Comptes Rendus. Géoscience, Volume 356 (2024) no. G1, p. 1 | DOI:10.5802/crgeos.256
- Recent progress in identification of the geomagnetic signature of 3D outer core flows, Acta Geodaetica et Geophysica, Volume 55 (2020) no. 3, p. 347 | DOI:10.1007/s40328-020-00307-3
- Fluid Dynamics of Earth’s Core: Geodynamo, Inner Core Dynamics, Core Formation, Fluid Mechanics of Planets and Stars, Volume 595 (2020), p. 129 | DOI:10.1007/978-3-030-22074-7_5
- Chemical Convection and Stratification in the Earth's Outer Core, Frontiers in Earth Science, Volume 7 (2019) | DOI:10.3389/feart.2019.00099
- Rotating convective turbulence in Earth and planetary cores, Physics of the Earth and Planetary Interiors, Volume 246 (2015), p. 52 | DOI:10.1016/j.pepi.2015.07.001
- Turbulence in the Core, Treatise on Geophysics (2015), p. 161 | DOI:10.1016/b978-0-444-53802-4.00142-1
- A turbulent, high magnetic Reynolds number experimental model of Earth's core, Journal of Geophysical Research: Solid Earth, Volume 119 (2014) no. 6, p. 4538 | DOI:10.1002/2013jb010733
- References, Magnetic Processes in Astrophysics (2013), p. 327 | DOI:10.1002/9783527648924.refs
- Zonal shear and super-rotation in a magnetized spherical Couette-flow experiment, Physical Review E, Volume 83 (2011) no. 6 | DOI:10.1103/physreve.83.066310
- Selection of inertial modes in spherical Couette flow, Physical Review E, Volume 81 (2010) no. 2 | DOI:10.1103/physreve.81.026311
- Short Timescale Core Dynamics: Theory and Observations, Space Science Reviews, Volume 155 (2010) no. 1-4, p. 177 | DOI:10.1007/s11214-010-9691-6
- Short Timescale Core Dynamics: Theory and Observations, Terrestrial Magnetism, Volume 36 (2010), p. 177 | DOI:10.1007/978-1-4419-7955-1_8
Cité par 12 documents. Sources : Crossref
Commentaires - Politique
Vous devez vous connecter pour continuer.
S'authentifier